In the digital era where all kinds of electrical equipments aim to the intelligent development, the communication and information sharing among the equipments has become the general trend of the modern industry and even the human life's requirement. In the field of data communications, data transmission technology is one of the most important and the most basic technology.
Various data transmission technologies have emerged, including wired data communication such as Modbus, CAN bus, USB, Ethernet, as well as wireless data communication such as WIFI, ZigBee, Bluetooth, NFC, etc.
The methods for the Wired data transmission mentioned have to change the structure of the existing equipment and also need to add driving chips and memory, some of them further require network infrastructures and various protection measures, such as an antistatic protection, an insulation protection and the like, which cause significant increases in system cost.
In above methods for the wireless data transmission, locations of antennas are subjected to several limitations, such as shielding, interference, and so on, which brings difficulty to the design of EMC/EMI. In the wireless data transmission method, there is further proposed an optical image method, wherein a display displays two-dimensional codes, and wherein data is read through shooting and scanning by mobile terminals such as a phone. This method would not change the hardware structure of the original equipment, but adds requirements for the display performance, such as a better contrast and a larger pixel dot density, such that the optical image data transmission method cannot be applied to some display instruments. In addition, displaying the two-dimensional codes on the display occupies some display area, and it will affect the display of the original contents and affect the actual usage.
In the digital era, various devices are required to have the function of data communication, and usually in the implementation of a new data transmission method, the original hardware system is needed to be modified, such that the original devices are forced to be dropped and replaced with new devices. However, when the devices are traded in, usually they are limited by various facilities, such as a space size, the network infrastructure, the environment and so on.
The backlight of the display in an instrument/meter is usually used for lighting the display and improving a readability of the display, but has no data transmission function. However, the present disclosure expects to overcome the problems existed in the prior art by means of a visible light communication technology developed recently, in order to make it possible to avoid alteration of the hardware system in the original devices and overcome the device compatibility issues, which would facilitate the promotion and usage of this technique.